Writing and drawing together on a common display often assist a working group in a
task. For example, facetoface groups have long enjoyed the richness of graphic
communication found on blackboards. The spontaneous image manipulations which take
place over time on a blackboard can be viewed as a textgraphic performance. A
human performer generates and manipulates text and graphics for the purpose of
assisting the working group in their task.

The phenomenon of performed textgraphics presents opportunities for research in the
area of computersupported cooperative work. 1] Spontaneous generation demands a
performing medium where the focus is on live manipulation of text and graphics.
Design of a computerbased medium with enough agility and generality to support
blackboardlike activity is a challenge for interface design. 2] Agility and
generality must not be achieved at the expense of specializability. After a group
has initially sketched an idea in text and graphics, then that same medium should
also support refining the sketch according to formal schema. 3] The performing
medium can also be used as a recording medium for studying image manipulation as
part of the working group process.

This paper presents a stepwise approach to the design of a performing medium for
working group graphics. First, examples of noncomputer textgraphics for groups are
examined to get a preliminary idea of the underlying phenomenon: the performing of
textgraphic manipulation to assist working groups. Next key features of that kind of
textgraphic manipulation are isolated. Then, third, the architecture and behavior of
a graphics editor providing those features is described.

Published in the proceedings of the CONFERENCE ON COMPUTER-SUPPORTED COOPERATIVE WORK,
Austin, Texas, December 3-5, 1986; reprinted as a
chapter in COMPUTER-SUPPORTED COOPERATIVE WORK: A Book of Readings, edited
by Greif, Irene, Morgan Kaufman Publishers, Palo Alto, 1988.